We all feed our horses. Some by nutritional neglect, others by rigid requirements and everyone else on a spectrum of husbandry between the two extremes.
Each horse has a nutritional requirement but there is a large latitude of nutritional variance that the horse can compromise and live under for a certain length of time. The survivability and level of performance will depend on breed, age, gender and athletic nutritional requirements. The well-being and performance of the individual will depend on the quantity and quality of feedstuffs consumed by the horse.
Nutrition consists of feedstuffs made of a combination of Crude Protein (CP), Carbohydrates or Sugars, Fats, vitamins, minerals and Non-Digestible Fiber (NDF). There is no perfect feedstuff having the right combination of ingredients for the horse. Consequently we need to adjust feedstuffs to offer at least the minimum nutritional requirement of each ingredient. Therefore a large variances in a diet can still meet the nutritional requirement of the horse. When athletic performance nutritional requirements are added to minimum nutritional requirement, the diet has to have a higher degree of management.
Protein requirement like other nutritional requirements depend on the horses age and workload. Protein is generally discussed as crude protein. In looking at any feed label the percent of crude protein listed means that for every 100 lbs. of feed, the listed number of Crude Protein is the amount in the feed. Or since requirements are listed in grams, for every kilogram or 1000gms of feed stuff, there is that percentage or grams of protein. So if the feed stuff is 12% CP, every kilogram (Kg) of feed stuff has 12gms of protein or for every 100 lbs. of feedstuff, has 12 lbs. of protein.
Although diets are figured on Crude Protein. Crude Proteins are made up of building blocks call amino acids. Depending on the cell type, specific amino acids are required. Not all proteins meet the quantity of amino acids the horse needs. Generally if we balance a diet for crude protein, the resulting amino acid profile is significant enough.
As the horse matures the percent Crude Protein diet requirement decreases but workload starts influencing the horse’s Crude Protein requirement. Since a foal, weanling and yearling are growing more of the building blocks are needed to grow. Foals diets should be supplemented with an 18% CP diet as the mare’s milk starts to diminish in quantity. Weanling should be fed a 16% CP diet. The amount of protein will depend on the desired mature weight and breed of the individual horse.
As a yearling since the horse is not growing as fast, a 14% CP diet should be fed. A two year old will require a 12% CP diet dictated more by growth of the breed and individual horse. Mature horses require an 11% CP diet. Athletic workload will have a requirement on the CP. Beside some protein being used for energy, the athlete requires the amino acids to repair tissue. The gender and reproductive performance of the individual will influence the protein requirement. Broodmares especially in the last trimester of pregnancy and breeding stallions will have a higher protein requirement then geldings.
In regards to feedstuff available to meet the horse’s protein requirement, grains are generally more protein dense then grasses. The exception in hay is alfalfa. Alfalfa has a higher percentage of CP verses grass hays 17-20% vs 6-12% respectively. To determine the amount protein fed, the weight of the feedstuff needs to be determined not the volume. Most clients feed on volume, so many flakes of hay or a scoop of feed. But to determine if the horse is being feed enough, the client needs to determine the weight of each feedstuff given to the horse. A weight in kilograms is much easier to figure then a weight in pounds.
Once the weight of the feedstuff is determined, multiply the weight by the percentage of CP to determine the amount of protein. Determine the amount of protein in each feedstuff, add the amounts together to determine the total amount of protein fed to your horse per day. The protein amount can be compared to the NRC (National Research Councils) charts of requirements. Let’s do an example, if your horse is fed 22 lbs. of brome hay/day with a feed analysis for the hay at 6% CP. 22 lbs. of hay equals 10 kg of brome hay multiply by the percent CP as a decimal (10 X .06) equals 600 gm of protein/day for your horse.
A component of the diet puzzle is the horse is limited in the amount of feedstuffs it can consume in a 24 hour period. The horse can consume about 2 – 2.5% of their body weight. For example a 1000 lb. horse will consume 20 – 25lbs./day. This limitation has to be taken into consideration when figuring out the feedstuffs to put in your horses diet. Also in regards to the diet dilemma, how much is the horse grazing and what is the maturity level of the pasture. Crude protein levels in pasture change with the grass growth. For instants fescue grass can have a CP level of the low 20’s around the beginning of May and be down to 5% by the third week of May.
So when horse owners buy brome hay, most do not ask when the hay was cut and baled. Brome hay in the Missouri/Kansas region if cut the last week of May will have around a 12% CP but if baled after the third week of June may have a 6% CP. This is quite a protein swing. 10 kg of May cut hay will provide 1200gm of protein where a late June cut hay may have 600gm protein. That is a 600gm protein swing which may make your horse’s diet deficient in protein. Asking hay producers when the hay was cut and if it was rained on are pertinent questions.
Bioavailability or absorption of the feedstuffs by your horse needs to be addressed. Just because your horse ingests all of their feed stuff does not mean they absorb all of it out of the intestinal tract. As the horse matures intestinal absorption and metabolism changes. Also as the horse ages, their saliva production which is needed for digestion will decrease. Consequently a larger percentage of the protein in the diet is lost with the feces. To overcome this age-related decrease in function more protein needs to be provided. I see a realization of this fact as clients athletic horses age and lose their backline muscle mass.
Muscle is lost starting behind the withers and works toward the rump. This muscle loss is hampered by sacropelvic biomechanical problems and the loss of true collection. In addition to the incorrect biomechanics creating a lack of use atrophy, muscle catabolism occurs due to a low protein diet. The low protein diet arises when an owner does not want to feed the horse as much for weight control or attitude control. To correct this issue a higher protein diet with the correct amino acid profile along with chiropractic adjustments to return proper biomechanical function is required. As the horse ages it is harder to return this muscle mass.
In conclusion, the feeding and nutritional component of horse care is a multi-faceted issue. As horses’ age, metabolic requirements and function change. Alongside of the horses’ requirements is the variability of the feedstuffs available to the horse. It can be a complex issue to solve and properly feeding your horse is a necessity. It is always wise to use a professional to help determine if you are feeding your horse properly or not. For assistance with your horse’s diet and proper biomechanical movement give Dr Wagner a call or contact him through this website.